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Neutron diffraction studies on the magnetic structures of the topologically nontrivial itinerant kagome antiferromagnet, YMn<sub>6</sub>Sn<sub>6</sub>

ORAL

Abstract

YMn6Sn6 exhibits topologically protected characteristics which are unusual given the underlying centrosymmetric crystal lattice (P6/mmm). In zero-applied magnetic field, polarized neutron diffraction measurements presented here show a preferential spin chirality in the double flat spiral spin state. At elevated temperatures and modest in-plane magnetic fields, a topological Hall effect emerges, [1,2] despite a null scalar spin chirality. The competing magnetic exchange interactions in this material are delicately balanced due to frustration and as a result, thermal fluctuations, temperature, and applied magnetic fields can drive the system into a number of different magnetic phases. Unpolarized neutron diffraction measurements were used to solve the structure of many of these phases and will also be presented. These measurements neatly explain the multiple features seen in ac susceptibility measurements, [1] and our corresponding theoretical studies align with the experimental evidence to provide a satisfyingly complete picture of the in-field magnetic phase diagram for YMn6Sn6.

[1] Ghimire, N. J., et al. arXiv preprint arXiv:2007.02399 (2020).
[2] Wang, Q., et al. arXiv preprint arXiv:1906.07986 (2019).

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Presenters

  • Rebecca Dally

    NIST Center for Neutron Research, National Institute of Standards and Technology

Authors

  • Rebecca Dally

    NIST Center for Neutron Research, National Institute of Standards and Technology

  • Nirmal Jeevi Ghimire

    George Mason University, Argonne National Laboratory, Physics and Astronomy, George Mason University, Department of Physics and Astronomy, George Mason University, Physics, George Mason University

  • David Connor Jones

    Department of Physics and Astronomy, George Mason University

  • Dina Michel

    Department of Physics and Astronomy, George Mason University

  • Michael A McGuire

    Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge National Lab, Oak Ridge National Laboratory

  • J Samuel Jiang

    Argonne National Laboratory, Materials Science Division, Argonne National Laboratory

  • John Mitchell

    Argonne National Laboratory, Materials Science Division, Argonne National Laboratory

  • Jeffrey W Lynn

    Center for Neutron Research, National Institute of Standards and Technology, NIST Center for Neutron Research, National Institute of Standards and Technology, Quantum Materials Center, University of Maryland, College Park, NIST Center for Neutron Research, National Institute of Standards and Technology

  • Igor Mazin

    Physics & Astronomy, George Mason University, Department of Physics and Astronomy, George Mason University, George Mason University, Physics and Astronomy, George Mason University, Physics, George Mason University, Department of Physics and Astronomy,, George Mason University, Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA